Gravity produces forces on the body. Methods of counteracting these forces have been devised for therapeutic as well as physical training uses. One way to counteract the effects of gravity on a body is to attach elastic cords at the waist and/or shoulder to produce either a positive or negative vertical force on the individual.
Other systems may use differential air pressure to simulate a low gravity effect, for example as described in U.S. Patent Publication No. 2007/0181121, which is incorporated herein by reference in its entirety.
A need exists for improved differential air pressure systems to be used for therapeutic and/or physical training uses.